Connect public, paid and private patent data with Google Patents Public Datasets

Inferring temperature of a heated exhaust gas oxygen sensor

Download PDF

Info

Publication number
US5605040A
US5605040A US08412663 US41266395A US5605040A US 5605040 A US5605040 A US 5605040A US 08412663 US08412663 US 08412663 US 41266395 A US41266395 A US 41266395A US 5605040 A US5605040 A US 5605040A
Authority
US
Grant status
Grant
Patent type
Prior art keywords
sensor
ego
ext
temperature
catalyst
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
US08412663
Inventor
Michael J. Cullen
Paul F. Smith
Thomas S. Gee
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ford Global Technologies LLC
Original Assignee
Ford Motor Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Grant date

Links

Images

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02DCONTROLLING COMBUSTION ENGINES
    • F02D41/00Electrical control of supply of combustible mixture or its constituents
    • F02D41/02Circuit arrangements for generating control signals
    • F02D41/14Introducing closed-loop corrections
    • F02D41/1438Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
    • F02D41/1493Details
    • F02D41/1494Control of sensor heater
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02DCONTROLLING COMBUSTION ENGINES
    • F02D41/00Electrical control of supply of combustible mixture or its constituents
    • F02D41/02Circuit arrangements for generating control signals
    • F02D41/14Introducing closed-loop corrections
    • F02D41/1401Introducing closed-loop corrections characterised by the control or regulation method
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02DCONTROLLING COMBUSTION ENGINES
    • F02D41/00Electrical control of supply of combustible mixture or its constituents
    • F02D41/02Circuit arrangements for generating control signals
    • F02D41/14Introducing closed-loop corrections
    • F02D41/1438Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
    • F02D41/1439Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the position of the sensor
    • F02D41/1441Plural sensors
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2240/00Combination or association of two or more different exhaust treating devices, or of at least one such device with an auxiliary device, not covered by indexing codes F01N2230/00 or F01N2250/00, one of the devices being
    • F01N2240/02Combination or association of two or more different exhaust treating devices, or of at least one such device with an auxiliary device, not covered by indexing codes F01N2230/00 or F01N2250/00, one of the devices being a heat exchanger
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2410/00By-passing, at least partially, exhaust from inlet to outlet of apparatus, to atmosphere or to other device
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/10Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
    • F01N3/18Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
    • F01N3/20Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters

Abstract

A method of inferring the temperature of a heated exhaust gas oxygen sensor is used in the control of the operation of an electronic engine control for an internal combustion engine.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to electronic engine controls for operation of an internal combustion engine.

2. Prior Art

It is known to control the air fuel ratio of an internal combustion engine using various air fuel control strategies. Factors such as ambient air pressure, mass air flow, and intake air temperature have been used in the process of controlling air fuel ratio for an internal combustion engine.

Further, the proper operation of a catalyst processing the exhaust gas from an internal combustion engine depends, in part, upon the air fuel ratio supplied to the engine. Associated with the downstream flow of exhaust gas and the catalyst it is known to use an exhaust gas oxygen sensor to sense the concentration of oxygen in the exhaust gas. Knowledge of the exhaust gas oxygen concentration can be used to control the air fuel ratio.

Previous approaches have used exhaust gas temperature prediction strategy based upon the catalyst midbed temperature in the exhaust gas.

It would be desirable to improve control of the air fuel ratio in an engine by better taking into account the operating conditions of the engine, including exhaust gas oxygen sensor temperature.

SUMMARY OF THE INVENTION

This invention recognizes that exhaust gas oxygen sensor temperature can be inferred. If desired, the temperature can be used to implement adjustments to engine control that would improve overall performance of the engine.

The invention also takes into account that the heated exhaust gas oxygen sensor has its own time constant for temperature changes since it has its own thermal capacitance. This time constant has been found to be a function of the exhaust gas flow rate which equals the air mass flow rate, AM.

The invention further recognizes that the exhaust gas oxygen sensor temperature can have a temperature offset from the exhaust gas temperature since part of the exhaust gas oxygen sensor assembly is exposed to the atmosphere and part to the metal exhaust pipe.

This invention further recognizes that knowledge of the exhaust gas oxygen sensor temperature can have at least two purposes:

1) determining when water vapor is no longer present near the exhaust gas oxygen sensor so the heater can be turned on without ceramic cracking,

2) deciding when to turn the heater off to protect it from over temperature.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a block diagram of an engine and control system in accordance with an embodiment of this invention.

FIGS. 2A and 2B are a logic flow chart in accordance with an embodiment of this invention.

DETAILED DESCRIPTION OF THE DISCLOSURE

Referring to FIG. 1, an engine 10 has an exhaust gas path 12 coupled to a catalyst 11. An exhaust gas oxygen (EGO) sensor 13, including a heater, is positioned in the exhaust gas flow upstream of catalyst 11 and an exhaust gas oxygen sensor 14, including a heater, is positioned in the exhaust gas flow downstream of catalyst 11. Associated with each sensor 13 and 14 is a resistance heater for providing selective heating of sensors 13 and 14. Output signals from sensors 13 and 14 are applied to an electronic engine control (EEC) module 18 which contains an engine control strategy and produces an output applied to fuel injector 16, which controls fuel injection into engine 10.

When the engine is started a timing sensor associated with an engine electronic engine control (EEC) system indicates the time since the vehicle was last turned off and this value is stored in SOAKTIME, the magnitude representing seconds. The front EGO sensor tip temperature EXT-- FET (Front Ego sensor Tip) is modelled as the sum at the unheated tip temperature EXT-- FEU (Front Ego sensor Unheated) and the effect of the electrical resistance heater EXT-- FEH (Front Ego sensor Heat).

In initialization, each of these components is assumed to cool off with a first order time constant. The EEC exponential function FNEXP is used to predict the temperature components at any time SOAKTIME after the car was turned off. The temperature components value at car turn off are stored in keep alive memory KAM. INFAMB is the inferred or measured ambient temperature. Analogous logic is used for the rear EGO sensor tip temperature.

Referring to FIGS. 2A and 2B, the method of inferring temperature of a heated exhaust gas oxygen sensor starts at a decision block 200 wherein it is asked whether a variable has been initialized. EXT-- INIT is a boolean variable that is set to FALSE by the EEC only once, during the first background loop of engine strategy operation. If at decision block 200, EXT-- INIT does not equal FALSE, the initialization process is skipped and the logic flow continues on to a block 202. If EXT-- INIT equals FALSE, logic flow goes on to a block 201 wherein the variables are initialized.

The temperature in degrees of unheated front exhaust gas oxygen sensor 13 (EXT-- FEU) is determined by the following formula: INFAMB+FNEXP(-SOAKTIME/TC-- SOAK-- FEU) * (EXT-- FEU-- PREV-INFAMB) where INFAMB is the inferred ambient temperature in degrees, FNEXP(x) is a lookup table representing the constant e raised to the x, SOAKTIME is the amount of time in seconds that has lapsed since the engine was last turned off, TC-- SOAK-- FEU is a calibrateable time constant in degrees per second that describes the speed at which unheated front EGO sensor 13 (EXT-- FEU) will cool off after the engine is turned off and EXT-- FEU-- PREV is the temperature in degrees of unheated front EGO sensor 13 from the previous background loop, before the engine was last turned off. The effect of the heat in degrees that has been applied by the resistance heater to front EGO sensor 13 (EXT-- FEH) is determined by the following formula: INFAMB+FNEXP(-SOAKTIME/TC-- SOAK-- FEH) * (EXT-- FEH-- PREV-INFAMB) where TC-- SOAK-- FEH is a calibrateable time constant in degrees per second that describes the speed at which the heat applied to front EGO sensor 13 will dissipate and EXT-- FEH-- PREV is the effect of the heat in degrees that was applied during the previous background loop.

The temperature in degrees of the tip of front EGO sensor 13 (EXT-- FET) is determined by the following formula: EXT-- FEU+EXT-- FEH. The temperature in degrees of unheated rear EGO sensor 14 (EXT-- REU) is determined by the following formula: INFAMB+FNEXP(-SOAKTIME/TC-- SOAK-- REU) * (EXT-- REU-- PREV-INFAMB) where TC-- SOAK-- REU is a calibrateable constant in degrees per second that describes the speed at which unheated rear EGO sensor 14 (EXT-- REU) will cool off after the engine is turned off and EXT-- REU-- PREV is the temperature in degrees of unheated rear EGO sensor 14 from the previous background loop. The effect of the heat in degrees that has been applied by the resistance heater to rear EGO sensor 14 (EXT-- REH) is determined by the following formula: INFAMB+FNEXP(-SOAKTIME/TC-- SOAK-- REH) * (EXT-- REH-- PREV-INFAMB) where TC-- SOAK-- REH is a calibrateable time constant in degrees per second that describes the speed at which the heat applied to rear EGO sensor 14 will dissipate and EXT-- REH-- PREV is the effect of the heat in degrees that was applied during the previous background loop. The temperature in degrees of the tip of rear EGO sensor 14 (EXT-- RET) is determined by the following formula: EXT-- REU+EXT-- REH. The last step of initialization is to set the "initialized" flag (EXT-- INIT) to TRUE.

From block 201 logic goes to block 202 wherein the temperature of unheated front EGO sensor 13 tip (EXT-- FEU) is determined. This is done in four steps. The first step is to calculate the temperature loss from the exhaust flange gas temperature to the front EGO sensor 13 temperature (EXT-- LS-- FEU) using the following formula: FN443L(AM) * [(EXT-- FL+EXT-- FEU-- PREV)/2-INFAMB] where FN443L(AM) is a table of temperature loss versus a temperature difference calculation. The temperature difference is the average of the exhaust flange gas temperature (EXT-- FL) and the front EGO sensor 13 tip temperature from the previous background loop (EXT-- FEU-- PREV) minus the ambient temperature (INFAMB). The second step is to calculate the steady state temperature in degrees of unheated front EGO sensor 13 (EXT-- SS-- FEU) using the following formula: EXT-- FL-EXT-- LS-- FEU. The third step is to calculate the time constant in degrees per second that describes the speed at which the heat from the exhaust of a running engine will change the temperature of the tip of front EGO sensor 13 (TC-- FEU-- RUN) by using the function FN443(AM) which determines the time constant for instantaneous front heated gas oxygen sensor (HEGO) wall temperature versus air mass (AM). The fourth step to determining the temperature of unheated front EGO sensor 13 (EXT-- FEU) is to calculate the rolling average in degrees of the steady state temperature in degrees of unheated front ego sensor 13 (EXT-- SS-- FEU). The rolling average is an average value of a parameter of time. One example would be to have a buffer of fixed length (10 registers) which has the value of the parameter placed into it at a fixed time interval (every one second). If a constant value (3) is put into the buffer every one second, in ten seconds, the buffer would be full of 3's and the rolling average would be 3. The buffer works in a first in first out fashion. In fifteen seconds, the first five 3's would have flowed out of the buffer and five seconds worth of new 3's would have flowed in. The rolling average would still be 3. If at 15 seconds, the constant value was changed to 2. At twenty seconds the buffer would contain five 3's and five 2's. The rolling average would be 2.5. At 25 seconds the buffer would contain ten 2's and the rolling average would be 2. The length of the buffer determines how long it will take the rolling average to reach the steady state value. In this example, the steady state value is 2 and the time it took to get there is ten seconds. The length of time required for the rolling average to change 63.2% of the step change is called one time constant (TC) The time constant is calculated by the following formula: 0.632*(old value-new value). In this example, the time constant would be 0.632*(3-2) or 0.623. The buffer model breaks down into the following equation: new rolling average=old rolling average+((new data point-old rolling average)*(1-e**(-t/TC))) where t is the amount of time in seconds that has elapsed.

The EEC does not use a buffer approach. Instead, a rolling average in the form of EXT-- FEU=ROLAV(EXT-- SS-- FEU, TC-- REU-- RUN) which approximates the above formula is used. The EEC interprets such an instruction to move EXT-- FEU from its present value toward EXT-- SS-- FEU at a time constant of TC-- FEU-- RUN. An instantaneous value of the front EGO sensor, EXT-- FEU, is then calculated as a function of the steady state front EGO temperature EXT-- SS-- FEU, the time constant of the temperature rise, TC-- FEU-- RUN and the time required for execution of the background loop, BG-- TMR, according to the following relationships: EXT-- FEU=(1-FK) * EXT-- FEU+FK * EXT-- SS-- FEU where FK performs an exponential smoothing function according to the following relationship: FK=1/(1+TC-- FEU-- RUN/BG-- TMR).

From block 202, logic flow goes to a decision block 203 wherein it is asked if the front heater in on (FRONT-- HEATER-- ON). If no, logic flow goes to a block 204 which sets the temperature in degrees of applied heat (EXT-- SS-- FEH) to 0. Then logic flow continues on to block 206.

If, at decision block 203, the front heater is on, logic flow goes to a block 205 which determines the effect of the heat in degrees that has been applied to the tip of front EGO sensor 13. This is done by using a linear equation versus the EGO temperature in the following formula: EXT-- FEH-- INT-EXT-- FEH-- SLP * EXT-- FEU where EXT-- FEH-- INT is the intercept of the applied heat, EXT-- FEH-- SLP is the slope of the applied heat and EXT-- FEU is the temperature in degrees of unheated front EGO sensor 13. As an alternate embodiment of the above formula, one could allow for more complex behavior by having a table look up of the effect of the applied heat (EXT-- SS-- FEH) versus the temperature of unheated front EGO sensor 13 (EXT-- FEU) with piece-wise linear interpolation.

From block 205, logic flow goes to a block 206 wherein the speed in degrees per second at which the tip of front EGO sensor 13 will heat is determined. This is done by setting a calibrateable constant that describes the speed at which front EGO sensor 13 will heat up (TC-- FEH-- RUN). As an alternate embodiment, this constant could be a look up table versus air mass (AM). Yet another alternate embodiment would be a look up table versus the temperature of unheated front EGO sensor 13 (EXT-- FEU). Logic flow then goes to a block 207 which determines the current temperature in degrees of the tip of front EGO sensor 13 (EXT-- FET). This is a two step process.

The first step is to calculate the rolling average of the amount of heat that was applied to front EGO sensor 13 by the resistance heater (EXT-- SS-- FEH). The second step finds the current temperature in degrees of the tip of front EGO sensor 13 (EXT-- FET) by adding the temperature in degrees of unheated front EGO sensor 13 (EXT-- FEU) and the temperature in degrees of the effect of the heat applied by the resistance heater (EXT-- FEH). From block 207, logic flow continues on to a block 208 which updates the previous value of the temperature in degrees of unheated front EGO sensor 13 (EXT-- FEU-- PREV) with the current value of the temperature in degrees of unheated front EGO sensor 13 (EXT-- FEU) for use in the next background loop.

From logic block 208, logic flow goes on to a block 209 wherein the temperature of unheated rear EGO sensor 14 tip (EXT-- REU) is determined. This is done in four steps. The first step is to calculate the temperature loss from the catalytic convertor midbed gas temperature to the rear EGO sensor 14 temperature (EXT-- LS-- REU) using the following formula: FN450L(AM) * [(EXT-- CMD+EXT-- REU-- PREV)/2-INFAMB] where FN450L(AM) is a table of temperature loss versus a temperature difference calculation. The temperature difference is the average of the catalytic converter midbed gas temperature (EXT-- CMD) and rear EGO sensor 14 tip temperature from the previous background loop (EXT-- REU-- PREV) minus the ambient temperature (INFAMB). The second step is to calculate the steady state temperature in degrees of unheated rear EGO sensor 14 (EXT-- SS-- REU) using the following formula: EXT-- CMD-EXT-- LS-- REU. The third step is to calculate the time constant in degrees per second that describes the speed at which the heat from the exhaust of a running engine will change the temperature of the tip of rear EGO sensor 14 (TC-- REU-- RUN) by using the function FN450(AM) which determines the time constant for instantaneous rear heated gas oxygen sensor (HEGO) wall temperature versus air mass (AM). The fourth step to determining the temperature of unheated rear EGO sensor 14 (EXT-- REU) is to calculate the rolling average in degrees of the steady state temperature in degrees of unheated rear EGO sensor 14 (EXT-- SS-- REU).

From block 209, logic flow goes to a decision block 210 wherein it is asked if the rear heater is on (REAR-- HEATER-- ON). If no, logic flow goes to a block 211 which sets the temperature in degrees of applied heat (EXT-- SS-- REH) to 0. Then logic flow continues on to a block 213. If, at decision block 210, the rear heater is on, logic flow goes to a block 212 which determines the effect of the heat in degrees that has been applied to the tip of rear EGO sensor 14. This is done by using a linear equation versus the EGO temperature in the following formula: EXT-- REH-- INT-EXT-- REH-- SLP * EXT-- REU where EXT-- REH-- INT is the intercept of the applied heat, EXT-- REH-- SLP is the slope of the applied heat and EXT-- REU is the temperature in degrees of unheated rear EGO sensor 14. As an alternate embodiment of the above formula, one could allow for more complex behavior by having a table look up of the effect of the applied heat (EXT-- SS-- REH) versus the temperature of rear EGO sensor 14 (EXT-- REU) with piece-wise linear interpolation. From block 212, logic flow goes to a block 213 wherein the speed in degrees per second at which the tip of rear EGO sensor 14 will heat is determined. This is done by setting a calibrateable constant that describes the speed at which rear EGO sensor 14 will heat up (TC-- REH-- RUN). As an alternate embodiment, this constant could be a look up from a table versus air mass (AM). Yet another alternate embodiment would be a lookup table versus the temperature of rear EGO sensor 14 (EXT-- REU).

From block 213, logic flow then goes to a block 214 which determines the current temperature in degrees of the tip of the rear EGO (EXT-- RET). This is a two step process. The first step is to calculate the rolling average of the amount of heat that was applied to the rear EGO by the resistance heater (EXT-- SS-- REH). The second step finds the current temperature in degrees of the tip of rear EGO sensor 14 (EXT-- RET) by adding the temperature in degrees of unheated rear EGO sensor 14 (EXT-- REU) and the temperature in degrees of the effect of the heat applied by the resistance heater (EXT-- REH). From block 214, logic flow continues on to a block 215 which updates the previous value of the temperature in degrees of unheated rear EGO sensor 14 (EXT-- REU-- PREV) with the current value of the temperature in degrees of unheated rear EGO sensor 14 (EXT-- REU) for use in the next background loop.

Various modifications and variations will no doubt occur to those skilled in the arts to which this invention pertains. These and all other variations which basically rely on the teachings through which this disclosure has advanced the art are properly considered within the scope of this invention.

Claims (19)

We claim:
1. A method of controlling the operation of an internal combustion engine producing exhaust gas wherein controlling the air to fuel ratio includes the steps of:
establishing an exhaust gas temperature at startup to a function of time since the engine was turned off;
subtracting a temperature offset from the exhaust gas temperature;
calculating a time constant that describes the speed at which an exhaust gas oxygen (EGO) sensor heats up as a function of air mass; and
using a rolling average to predict the EGO sensor temperature as a function of said exhaust gas temperature at start-up, said temperature and said time constant.
2. A method of controlling the operation of an internal combustion engine as recited in claim 1 wherein the function of establishing the exhaust gas oxygen sensor temperature includes taking into account an estimate of ambient temperature and the magnitude of the last estimated temperature of said exhaust gas oxygen (EGO) sensor.
3. A method of controlling the operation of an internal combustion engine as recited in claim 2 further including a step of initializing the estimated temperature of a front pre-catalyst exhaust gas oxygen sensor of the internal combustion engine utilizing the following formula: INFAMB+FNEXP(-SOAKTIME/TC-- SOAK-- FEU) * (EXT-- FEU-- PREV-INFAMB) where INFAMB is the inferred ambient temperature, SOAKTIME is the amount of time since the engine was last turned off, TC-- SOAK-- FEU is a calibrateable time constant that describes the speed at which the heat applied to the front pre-catalyst EGO sensor will dissipate, EXT-- FEU-- PREV is the temperature of the front pre-catalyst EGO sensor in an unheated state from a previous background loop, requiring periodic determination of engine operation parameters, and FNEXP(x) is a lookup table representing the constant e raised to the x.
4. A method of controlling the operation of an internal combustion engine as recited in claim 2 further including initializing the estimated temperature of a rear post-catalyst exhaust gas oxygen sensor of an internal combustion engine utilizing the following formula: INFAMB+FNEXP(-SOAKTIME/TC-- SOAK-- REU) * (EXT-- REU-- PREV-INFAMB) where INFAMB is the inferred ambient temperature, SOAKTIME is the amount of time since the engine was last turned off, TC-- SOAK-- REU is a calibrateable time constant that describes the speed at which the heat applied to the rear post-catalyst EGO sensor will dissipate, EXT-- REU-- PREV is the temperature of the rear post-catalyst EGO sensor in an unheated state from the previous background loop and FNEXP(x) is a lookup table representing the constant e raised to the x.
5. A method of determining the temperature of an exhaust gas oxygen (EGO) sensor used with a heater in an electronic engine control for an engine having an exhaust utilizing a background loop including:
determining whether the temperatures of the EGO sensors have been initialized;
if the temperatures of the EGO sensors have not been initialized, initializing the temperature of the EGO sensors;
inferring the temperature of the EGO sensor by calculating a rolling average of the steady state temperature of the EGO sensor and a time constant which describes the speed at which the heat from the exhaust of a running engine will change the temperature of the tip of the EGO sensor;
determining whether the EGO sensor heater is on;
if the EGO sensor heater is not on, setting the amount of heat applied to the sensor to zero;
if the EGO sensor heater is on, finding the amount of applied heat by using a linear equation versus the EGO sensor temperature when the EGO sensor is in an unheated state;
determining the speed at which the EGO sensor tip will heat up using a calibrateable constant;
inferring the temperature of the EGO sensor in the unheated state by calculating the rolling average of the amount of heat that was applied to the tip of the EGO sensor and the time constant which describes the speed at which the EGO sensor will heat in the exhaust of a running engine;
inferring the temperature of the EGO sensor by adding the temperature increase due to the applied heat to the temperature of the EGO sensor in the unheated state; and
updating the stored value of the temperature of the EGO sensor in the unheated state from the previous background loop with the temperature of the unheated EGO sensor from the current background loop.
6. A method of determining the temperature of an exhaust gas oxygen sensor as recited in claim 5 further including the steps of:
determining the initial temperature of a front pre-catalyst EGO sensor in the unheated state utilizing the following formula: INFAMB+FNEXP(-SOAKTIME/TC-- SOAK-- FEU) * (EXT-- FEU-- PREV-INFAMB) where INFAMB is the inferred ambient temperature in degrees, FNEXP(x) is a lookup table representing the constant e raised to the x, SOAKTIME is the amount of time in seconds that has lapsed since the engine was last turned off, TC-- SOAK-- FEU is a calibrateable time constant in degrees per second that describes the speed at which the front pre-catalyst EGO sensor in the unheated state (EXT-- FEU) will cool off after the engine is turned off and EXT-- FEU-- PREV is the temperature in degrees of the front pre-catalyst EGO sensor in the unheated state from the previous background loop, before the engine was last turned off;
determining the amount of resistance heat remaining at the front pre-catalyst EGO tip utilizing the following formula: INFAMB+FNEXP(-SOAKTIME/TC-- SOAK-- FEH) * (EXT-- FEH-- PREV-INFAMB) where TC-- SOAK-- FEH is a calibrateable time constant in degrees per second that describes the speed at which the heat applied to front pre-catalyst EGO sensor will dissipate and EXT-- FEH-- PREV is the effect of the heat in degrees that was applied during the previous background loop;
determining the initial temperature of the tip of a heated front pre-catalyst EGO sensor utilizing the following formula: EXT-- FEU+EXT-- FEH where EXT-- FEU is the temperature of the front pre-catalyst EGO sensor in the unheated state and EXT-- FEH is the amount of heat applied to the front pre-catalyst EGO sensor by the resistance heater;
determining the initial temperature of a rear post-catalyst EGO sensor in the unheated state utilizing the following formula: INFAMB+FNEXP(-SOAKTIME/TC-- SOAK-- REU) * (EXT-- REU-- PREV-INFAMB) where INFAMB is the inferred ambient temperature in degrees, FNEXP(x) is a lookup table representing the constant e raised to the x, SOAKTIME is the amount of time in seconds that has lapsed since the engine was last turned off, TC-- SOAK-- REU is a calibrateable time constant in degrees per second that describes the speed at which the rear post-catalyst EGO sensor in the unheated state (EXT-- REU) will cool off after the engine is turned off and EXT-- REU-- PREV is the temperature in degrees of rear post-catalyst EGO sensor in the unheated state from the previous background loop, before the engine was last turned off;
determining the amount of resistance heat remaining at the front pre-catalyst EGO tip utilizing the following formula: INFAMB+FNEXP(-SOAKTIME/TC-- SOAK-- REH) * (EXT-- REH-- PREV-INFAMB) where TC-- SOAK-- REH is a calibrateable time constant in degrees per second that describes the speed at which the heat applied to rear post-catalyst EGO sensor will dissipate and EXT-- REH-- PREV is the effect of the heat in degrees that was applied during the previous background loop; and
determining the initial temperature of the tip of the rear post-catalyst EGO sensor utilizing the following formula: EXT-- REU+EXT-- REH where EXT-- REU is the temperature of the rear post-catalyst EGO sensor in the unheated state and EXT-- REH is the amount of heat applied to the rear post-catalyst EGO sensor by the resistance heater.
7. A method of determining the temperature of an exhaust gas oxygen sensor as recited in claim 5 further including:
calculating a temperature loss from a point near an exhaust flange to the EGO sensor utilizing the following formula: EXT-- LS-- FEU=FN443L(AM) * {(EXT-- FL+EXT-- FEU-- PREV)/2-INFAMB} where FN443L(AM) is a table of temperature loss that is multiplied by the average of the exhaust flange temperature and the EGO sensor temperature from the previous background loop minus the inferred ambient temperature;
calculating the steady state temperature of the EGO sensor utilizing the following formula: EXT-- SS-- FEU=EXT-- FL-EXT-- LS-- FEU where EXT-- FL is the temperature of a point near the exhaust flange and EXT-- LS-- FEU is the temperature loss between the exhaust flange and the EGO sensor;
calculating the time constant that describes the speed at which the heat from the exhaust of a running engine will dissipate from the tip of the front pre-catalyst EGO sensor utilizing a lookup table which determines the time constant for instantaneous front pre-catalyst EGO sensor wall temperature versus air mass (AM); and
calculating the rolling average of the steady state temperature of the front pre-catalyst EGO sensor in the unheated state and the effect of the heat of the exhaust of a running engine on the front pre-catalyst EGO sensor.
8. A method of determining the temperature of an exhaust gas oxygen (EGO) sensor as recited in claim 5 further including determining the amount of heat being applied to the tip of the front pre-catalyst EGO sensor utilizing a linear equation versus the front pre-catalyst EGO sensor temperature in the following formula: EXT-- SS FEH=EXT-- FEH-- INT-EXT-- FEH-- SLP * EXT-- FEU where EXT-- FEH-- INT is the intercept of the applied heat versus time, EXT-- FEH-- SLP is the slope of the applied heat versus time and EXT-- FEU is the temperature of the front pre-catalyst EGO sensor in the unheated state.
9. A method of determining the temperature of an exhaust gas oxygen (EGO) sensor as recited in claim 5 further including determining the amount of heat being applied to the tip of the front pre-catalyst EGO sensor utilizing a table look up of the effect of the applied heat (EXT-- SS-- FEH) versus the temperature of the front pre-catalyst EGO sensor in the unheated state with piece-wise linear interpolation.
10. A method of determining the temperature of an exhaust gas oxygen (EGO) sensor as recited in claim 5 further including determining the speed pre-catalyst EGO sensor will heat utilizing a look up table versus air mass (AM).
11. A method of determining the temperature of an exhaust gas oxygen (EGO) sensor as recited in claim 5 further including determining the speed at which the front pre-catalyst EGO sensor will heat utilizing a look up table versus temperature of the front pre-catalyst EGO sensor in the unheated state.
12. A method of determining the temperature of an exhaust gas oxygen (EGO) sensor as recited in claim 5 further including:
calculating the rolling average of the magnitude of the amount of heat applied to the front pre-catalyst EGO sensor by the resistance heater utilizing the amount of heat applied to the front pre-catalyst EGO sensor and the speed at which the front pre-catalyst EGO sensor will heat up;
calculating the current temperature of the front pre-catalyst EGO sensor utilizing the following formula: EXT-- FET=EXT-- FEU+EXT-- FEH where EXT-- FEU is the temperature of the front pre-catalyst EGO sensor in the unheated state and EXT-- FEH is the total amount of heat applied to the front pre-catalyst EGO sensor; and
updating the value of the temperature of the front pre-catalyst EGO sensor in the unheated state from the previous background loop (EXT-- FEU-- PREV) with the temperature of the front pre-catalyst EGO sensor from the current background loop (EXT-- FEU).
13. A method of determining the temperature of an exhaust gas oxygen (EGO) sensor as recited in claim 5 further including:
calculating the temperature loss from a point near a catalytic converter midbed in the engine exhaust to the EGO sensor utilizing the following formula: EXT-- LS-- REU=FN450L(AM) * {(EXT-- CMD+EXT-- REU-- PREV)/2-INFAMB} where FN450L(AM) is a table of temperature loss that is multiplied by the average of the catalytic converter midbed temperature and the EGO sensor temperature from the previous background loop minus the inferred ambient temperature;
calculating the steady state temperature of the EGO sensor utilizing the following formula: EXT-- SS-- REU=EXT-- CMD-EXT-- LS-- REU where EXT-- CMD is the temperature of the catalytic converter midbed and EXT-- LS-- REU is the temperature loss between the catalytic converter midbed and the EGO sensor;
calculating the time constant that describes the speed at which the heat from the exhaust of a running engine will dissipate from the tip of the rear post-catalyst EGO sensor utilizing a lookup table which determines the time constant for instantaneous rear post-catalyst EGO sensor wall temperature versus air mass (AM); and
calculating the rolling average of the steady state temperature of the unheated rear post-catalyst EGO sensor and taking into account the effect of the heat of the exhaust of a running engine on the rear post-catalyst EGO sensor.
14. A method of determining the temperature of an exhaust gas oxygen (EGO) sensor as recited in claim 5 further including determining the amount of heat being applied to the tip of the rear post-catalyst EGO sensor utilizing a linear equation versus the rear post-catalyst EGO sensor temperature in the following formula: EXT-- SS-- REH=EXT-- REH-- INT-EXT-- REH-- SLP * EXT-- REU where EXT-- REH-- INT is the intercept of the applied heat versus time, EXT-- REH-- SLP is the slope of the applied heat versus time and EXT-- REU is the temperature of the rear post-catalyst EGO sensor in the unheated state.
15. A method of determining the temperature of an exhaust gas oxygen (EGO) sensor as recited in claim 5 further including determining the amount of heat being applied to the tip of the rear post-catalyst EGO sensor utilizing a table look up of the effect of the applied heat (EXT-- SS-- REH) versus the temperature of the rear post-catalyst EGO sensor in the unheated state with piece-wise linear interpolation.
16. A method of determining the temperature of an exhaust gas oxygen (EGO) sensor as recited in claim 5 further including determining the speed post-catalyst EGO sensor will heat as recited in claim 5 utilizing a look up table versus air mass (AM).
17. A method of determining the temperature of an exhaust gas oxygen (EGO) sensor as recited in claim 5 further including determining the speed at which the rear post-catalyst EGO sensor will heat utilizing a look up table versus temperature of the rear post-catalyst EGO sensor in the unheated state.
18. A method of determining the temperature of an exhaust gas oxygen (EGO) sensor as recited in claim 5 further including:
calculating the rolling average of the heat applied to the rear post-catalyst EGO sensor by the resistance heater utilizing the amount of heat applied to the rear post-catalyst EGO sensor and the speed at which the rear post-catalyst EGO sensor will heat up;
calculating the current temperature of the rear post-catalyst EGO sensor utilizing the following formula: EXT-- RET=EXT-- REU+EXT-- REH where EXT-- REU is the temperature of the rear post-catalyst EGO sensor in the unheated state and EXT-- REH is the total amount of heat applied to the rear post-catalyst EGO sensor; and
updating the value of the temperature of the rear post-catalyst EGO sensor in the unheated state from the previous background loop (EXT-- REU-- PREV) with the temperature of the rear post-catalyst EGO sensor from the current background loop (EXT-- REU).
19. A method of determining the temperature of an exhaust gas oxygen sensor as recited in claim 5 further including:
determining the initial temperature of the front pre-catalyst EGO sensor in the unheated state utilizing the following formula: INFAMB+FNEXP(-SOAKTIME/TC-- SOAK-- FEU) * (EXT-- FEU-- PREV-INFAMB) where INFAMB is the inferred ambient temperature in degrees, FNEXP(x) is a lookup table representing the constant e raised to the x, SOAKTIME is the amount of time in seconds that has lapsed since the engine was last turned off, TC-- SOAK-- FEU is a calibrateable time constant in degrees per second that describes the speed at which front pre-catalyst EGO sensor in the unheated state (EXT-- FEU) will cool off after the engine is turned off and EXT-- FEU-- PREV is the temperature in degrees of front pre-catalyst EGO sensor in the unheated state from the previous background loop, before the engine was last turned off;
determining the amount of heat that was applied by the resistance heater to the front pre-catalyst EGO utilizing the following formula: INFAMB+FNEXP(-SOAKTIME/TC-- SOAK-- FEH) * (EXT-- FEH-- PREV-INFAMB) where TC-- SOAK-- FEH is a calibrateable time constant in degrees per second that describes the speed at which the heat applied to front pre-catalyst EGO sensor will dissipate and EXT-- FEH-- PREV is the effect of the heat in degrees that was applied during the previous background loop;
determining the initial temperature of the tip of the front pre-catalyst EGO sensor utilizing the following formula: EXT-- FEU+EXT-- FEH where EXT-- FEU is the temperature of the front pre-catalyst EGO sensor in the unheated state and EXT-- FEH is the amount of heat applied to the front pre-catalyst EGO sensor by the resistance heater;
determining the initial temperature of the rear post-catalyst EGO sensor in the unheated state utilizing the following formula: INFAMB+FNEXP(-SOAKTIME/TC-- SOAK-- REU) * (EXT-- REU PREV-INFAMB) where INFAMB is the inferred ambient temperature in degrees, FNEXP(x) is a lookup table representing the constant e raised to the x, SOAKTIME is the amount of time in seconds that has lapsed since the engine was last turned off, TC-- SOAK-- REU is a calibrateable time constant in degrees per second that describes the speed at which rear post-catalyst EGO sensor in the unheated state (EXT-- REU) will cool off after the engine is turned off and EXT-- REU-- PREV is the temperature in degrees of rear post-catalyst EGO sensor in the unheated state from the previous background loop, before the engine was last turned off;
determining the amount of heat that was applied by the resistance heater to the rear post-catalyst EGO utilizing the following formula: INFAMB+FNEXP(-SOAKTIME/TC-- SOAK-- REH) * (EXT-- REH-- PREV-INFAMB) where TC-- SOAK-- REH is a calibrateable time constant in degrees per second that describes the speed at which the heat applied to rear post-catalyst EGO sensor will dissipate and EXT-- REH-- PREV is the effect of the heat in degrees that was applied during the previous background loop;
determining the initial temperature of the tip of the rear post-catalyst EGO sensor utilizing the following formula: EXT-- REU+EXT-- REH where EXT-- REU is the temperature of the rear post-catalyst EGO sensor in the unheated state and EXT-- REH is the amount of heat applied to the rear post-catalyst EGO sensor by the resistance heater;
calculating a temperature loss from a point near an exhaust flange to the EGO sensor utilizing the following formula: EXT-- LS-- FEU=FN443L(AM) * {(EXT-- FL+EXT-- FEU-- PREV)/2-INFAMB} where FN443L(AM) is a table of temperature loss that is multiplied by the average of the exhaust flange temperature and the EGO sensor temperature from the previous background loop minus the inferred ambient temperature;
calculating the steady state temperature of the EGO sensor utilizing the following formula: EXT-- SS-- FEU=EXT-- FL-EXT-- LS-- FEU where EXT-- FL is the temperature of a point near the exhaust flange and EXT-- LS-- FEU is the temperature loss between the exhaust flange and the EGO sensor;
calculating the time constant that describes the speed at which the heat from the exhaust of a running engine will dissipate from the tip of the front pre-catalyst EGO sensor utilizing a lookup table which determines the time constant for instantaneous front pre-catalyst EGO sensor wall temperature versus air mass (AM);
calculating the rolling average of the steady state temperature of the front pre-catalyst EGO sensor in the unheated state and the effect of the heat of the exhaust of a running engine on the front pre-catalyst EGO sensor;
determining the amount of heat being applied to the tip of the front pre-catalyst EGO sensor utilizing a linear equation versus the front pre-catalyst EGO sensor temperature in the following formula: EXT-- SS-- FEH=EXT-- FEH-- INT-EXT-- FEH-- SLP * EXT-- FEU where EXT-- FEH-- INT is the intercept of the applied heat versus time, EXT-- FEH-- SLP is the slope of the applied heat versus time and EXT-- FEU is the temperature of the front pre-catalyst EGO sensor in the unheated state;
determining the amount of heat being applied to the tip of the front pre-catalyst EGO sensor utilizing a table look up of the effect of the applied heat (EXT-- SS-- FEH) versus the temperature of the front pre-catalyst EGO sensor in the unheated state with piece-wise linear interpolation;
determining the speed at which the front pre-catalyst EGO sensor will heat utilizing a look up table versus air mass (AM);
determining the speed at which the front pre-catalyst EGO sensor will heat utilizing a look up table versus temperature of the front pre-catalyst EGO sensor in the unheated state;
calculating the rolling average of the magnitude of the amount of heat applied to the front pre-catalyst EGO sensor by the resistance heater utilizing the amount of heat applied to the front pre-catalyst EGO sensor and the speed at which the front pre-catalyst EGO sensor will heat up;
calculating the current temperature of the front pre-catalyst EGO sensor utilizing the following formula: EXT-- FET=EXT-- FEU+EXT-- FEH where EXT-- FEU is the temperature of the front pre-catalyst EGO sensor in the unheated state and EXT-- FEH is the total amount of heat applied to the front pre-catalyst EGO sensor;
updating the value of the temperature of the front pre-catalyst EGO sensor in the unheated state from the previous background loop (EXT-- FEU-- PREV) with the temperature of the front pre-catalyst EGO sensor from the current background loop (EXT-- FEU);
calculating the temperature loss from a point near a catalytic converter midbed in the engine exhaust to the EGO sensor utilizing the following formula: EXT-- LS-- REU=FN450L(AM) * {(EXT-- CMD+EXT-- REU-- PREV)/2-INFAMB} where FN450L(AM) is a table of temperature loss that is multiplied by the average of the catalytic converter midbed temperature and the EGO sensor temperature from the previous background loop minus the inferred ambient temperature;
calculating the steady state temperature of the EGO sensor utilizing the following formula: EXT-- SS-- REU=EXT-- CMD-EXT-- LS-- REU where EXT-- CMD is the temperature of the catalytic converter midbed and EXT-- LS-- REU is the temperature loss between the catalytic converter midbed and the EGO sensor;
calculating the time constant that describes the speed at which the heat from the exhaust of a running engine will dissipate from the tip of the rear post-catalyst EGO sensor utilizing a lookup table which determines the time constant for instantaneous rear post-catalyst EGO sensor wall temperature versus air mass (AM);
calculating the rolling average of the steady state temperature of the rear post-catalyst EGO sensor in the unheated state and taking into account the effect of the heat of the exhaust of a running engine on the rear post-catalyst EGO sensor;
determining the amount of heat being applied to the tip of the rear post-catalyst EGO sensor utilizing a linear equation versus the rear post-catalyst EGO sensor temperature in the following formula: EXT-- SS-- REH=EXT-- REH-- INT-EXT-- REH-- SLP * EXT-- REU where EXT-- REH-- INT is the intercept of the applied heat versus time, EXT-- REH-- SLP is the slope of the applied heat versus time and EXT-- REU is the temperature of the rear post-catalyst EGO sensor in the unheated state;
determining the amount of heat being applied to the tip of the rear post-catalyst EGO sensor utilizing a table look up of the effect of the applied heat (EXT-- SS-- REH) versus the temperature of the rear post-catalyst EGO sensor in the unheated state with piece-wise linear interpolation;
determining the speed at which the rear post-catalyst EGO sensor will heat as recited in claim 5 utilizing a look up table versus air mass (AM);
determining the speed at which the rear post-catalyst EGO sensor will heat utilizing a look up table versus temperature of the rear post-catalyst EGO sensor in the unheated state;
calculating the rolling average of the heat applied to the rear post-catalyst EGO sensor by the resistance heater utilizing the amount of heat applied to the rear post-catalyst EGO sensor and the speed at which the rear post-catalyst EGO sensor will heat up;
calculating the current temperature of the rear post-catalyst EGO sensor utilizing the following formula: EXT-- RET=EXT-- REU+EXT-- REH where EXT-- REU is the temperature of the rear post-catalyst EGO sensor in the unheated state and EXT-- REH is the total amount of heat applied to the rear post-catalyst EGO sensor; and
updating the value of the temperature of the rear post-catalyst EGO sensor in the unheated state from the previous background loop (EXT-- REU-- PREV) with the temperature of the rear post-catalyst EGO sensor from the current background loop (EXT-- REU).
US08412663 1995-03-29 1995-03-29 Inferring temperature of a heated exhaust gas oxygen sensor Expired - Fee Related US5605040A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US08412663 US5605040A (en) 1995-03-29 1995-03-29 Inferring temperature of a heated exhaust gas oxygen sensor

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US08412663 US5605040A (en) 1995-03-29 1995-03-29 Inferring temperature of a heated exhaust gas oxygen sensor
US08885206 US5901553A (en) 1995-03-29 1997-06-30 Method and system for estimating temperature of a heated exhaust gas oxygen sensor in an exhaust system having a variable length pipe

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US08885206 Continuation-In-Part US5901553A (en) 1995-03-29 1997-06-30 Method and system for estimating temperature of a heated exhaust gas oxygen sensor in an exhaust system having a variable length pipe

Publications (1)

Publication Number Publication Date
US5605040A true US5605040A (en) 1997-02-25

Family

ID=23633906

Family Applications (1)

Application Number Title Priority Date Filing Date
US08412663 Expired - Fee Related US5605040A (en) 1995-03-29 1995-03-29 Inferring temperature of a heated exhaust gas oxygen sensor

Country Status (1)

Country Link
US (1) US5605040A (en)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5969230A (en) * 1996-11-19 1999-10-19 Unisia Jecs Corporation System and method for estimating the temperature of oxygen sensor installed in exhaust system of internal combustion engine
EP1069416A1 (en) * 1999-07-12 2001-01-17 Heraeus Electro-Nite International N.V. Method for decreasing the response time of a temperature sensor
EP1091108A1 (en) * 1999-10-06 2001-04-11 MAGNETI MARELLI S.p.A. Method for estimating the temperature of the exhaust gases upstream from a pre-catalyser, disposed along an exhaust pipe of an internal-combustion engine
US6393357B1 (en) 2000-07-17 2002-05-21 Ford Global Technologies, Inc. System and method for inferring engine oil temperature at startup
US6409969B1 (en) 1999-06-01 2002-06-25 Cummins, Inc. System and method for controlling a self-heated gas sensor based on sensor impedance
FR2834752A1 (en) * 2002-01-15 2003-07-18 Siemens Ag Method and device for determining an internal temperature in a catalyst
FR2839342A1 (en) * 2002-05-02 2003-11-07 Renault Sa Regulation of injection timing to internal combustion engine to optimize the conversion process of the catalyzer fitted to the engine, uses transducers on either side of exhaust catalytic converter to control richness using look-up table
US20040086023A1 (en) * 2002-10-31 2004-05-06 Smith James Craig Method and apparatus to control an exhaust gas sensor to a predetermined temperature
US20090312899A1 (en) * 2008-06-11 2009-12-17 Mitchell Bradley J Monitoring vehicle and equipment operations at an airport
US20090314069A1 (en) * 2008-06-11 2009-12-24 Mitchell Bradley J Method and apparatus for estimating engine power

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5167120A (en) * 1991-03-01 1992-12-01 Robert Bosch Gmbh Method of controlling the temperature of an exhaust gas probe
US5291673A (en) * 1992-12-21 1994-03-08 Ford Motor Company Oxygen sensor system with signal correction

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5167120A (en) * 1991-03-01 1992-12-01 Robert Bosch Gmbh Method of controlling the temperature of an exhaust gas probe
US5291673A (en) * 1992-12-21 1994-03-08 Ford Motor Company Oxygen sensor system with signal correction

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5969230A (en) * 1996-11-19 1999-10-19 Unisia Jecs Corporation System and method for estimating the temperature of oxygen sensor installed in exhaust system of internal combustion engine
US6409969B1 (en) 1999-06-01 2002-06-25 Cummins, Inc. System and method for controlling a self-heated gas sensor based on sensor impedance
EP1069416A1 (en) * 1999-07-12 2001-01-17 Heraeus Electro-Nite International N.V. Method for decreasing the response time of a temperature sensor
EP1091108A1 (en) * 1999-10-06 2001-04-11 MAGNETI MARELLI S.p.A. Method for estimating the temperature of the exhaust gases upstream from a pre-catalyser, disposed along an exhaust pipe of an internal-combustion engine
US6422000B1 (en) 1999-10-06 2002-07-23 MAGNETI MARELLI S.p.A. Method for estimating the temperature of the exhaust gases upstream from a pre-catalyser, disposed along an exhaust pipe of an internal-combustion engine
US6393357B1 (en) 2000-07-17 2002-05-21 Ford Global Technologies, Inc. System and method for inferring engine oil temperature at startup
FR2834752A1 (en) * 2002-01-15 2003-07-18 Siemens Ag Method and device for determining an internal temperature in a catalyst
FR2839342A1 (en) * 2002-05-02 2003-11-07 Renault Sa Regulation of injection timing to internal combustion engine to optimize the conversion process of the catalyzer fitted to the engine, uses transducers on either side of exhaust catalytic converter to control richness using look-up table
US20040086023A1 (en) * 2002-10-31 2004-05-06 Smith James Craig Method and apparatus to control an exhaust gas sensor to a predetermined temperature
US7036982B2 (en) 2002-10-31 2006-05-02 Delphi Technologies, Inc. Method and apparatus to control an exhaust gas sensor to a predetermined termperature
US20090312899A1 (en) * 2008-06-11 2009-12-17 Mitchell Bradley J Monitoring vehicle and equipment operations at an airport
US20090314069A1 (en) * 2008-06-11 2009-12-24 Mitchell Bradley J Method and apparatus for estimating engine power
US7870778B2 (en) * 2008-06-11 2011-01-18 The Boeing Company Method and apparatus for estimating engine power
US8335608B2 (en) 2008-06-11 2012-12-18 The Boeing Company Monitoring vehicle and equipment operations at an airport

Similar Documents

Publication Publication Date Title
US6758037B2 (en) Exhaust emission control device of engine
US6823663B2 (en) Exhaust gas aftertreatment systems
US5158063A (en) Air-fuel ratio control method for internal combustion engines
US6928806B2 (en) Exhaust gas aftertreatment systems
US5544639A (en) Temperature predicting system for internal combustion engine and temperature control system including same
US6904751B2 (en) Engine control and catalyst monitoring with downstream exhaust gas sensors
US5303168A (en) Engine operation to estimate and control exhaust catalytic converter temperature
US6973778B2 (en) Regeneration control of diesel particulate filter
US7013638B2 (en) Exhaust gas purifying system and exhaust gas purifying method
US5910096A (en) Temperature control system for emission device coupled to direct injection engines
US6948311B2 (en) Method and device for controlling an exhaust gas aftertreatment system
US7076944B2 (en) Exhaust gas cleaning system of internal combustion engine
US5928303A (en) Diagnostic system for diagnosing deterioration of heated type oxygen sensor for internal combustion engines
US5414994A (en) Method and apparatus to limit a midbed temperature of a catalytic converter
US6050086A (en) Exhaust emission control apparatus for internal combustion engine
US20090151332A1 (en) Exhaust gas purification system for internal combustion engine
US20030074892A1 (en) Apparatus and a method for controlling exhaust gas purification for a diesel engine
US5722236A (en) Adaptive exhaust temperature estimation and control
US5600948A (en) Engine air-fuel ratio controller
JP2002201998A (en) Controller of internal combustion engine
US5600947A (en) Method and system for estimating and controlling electrically heated catalyst temperature
US5902346A (en) Fuel delivery control based on estimated fuel temperature
US5390488A (en) Air injection control for preheated catalysts
US7320781B2 (en) Method for adjusting a reductant used in an internal combustion engine to reduce NOx
US6018945A (en) Air-fuel ratio control device for engine

Legal Events

Date Code Title Description
AS Assignment

Owner name: FORD MOTOR COMPANY, MICHIGAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:CULLEN,MICHAEL J.;SMITH, PAUL F.;GEE, THOMAS S.;REEL/FRAME:007497/0972

Effective date: 19950322

FPAY Fee payment

Year of fee payment: 4

AS Assignment

Owner name: FORD GLOBAL TECHNOLOGIES, INC. A MICHIGAN CORPORAT

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:FORD MOTOR COMPANY, A DELAWARE CORPORATION;REEL/FRAME:011467/0001

Effective date: 19970301

REMI Maintenance fee reminder mailed
LAPS Lapse for failure to pay maintenance fees
FP Expired due to failure to pay maintenance fee

Effective date: 20040225